One Answer:

Thanks for your question. As a general rule, mattresses that use Memory Foam as a comfort material over Foam as the support layer (like L&L) do not tend to excel at edge support. Loom & Leaf is no better -- but also no worse -- than other Memory Foam over Foam mattresses in this regard.

Practically speaking, how important this is for you depends on how you use the mattress and what your preferences / tolerances are. For example, you asked whether you can sit on the edge comfortably. If you are sitting on the edge briefly (eg, while tying your shoes), I would not expect you to have any problems doing this on a Loom & Leaf mattress, or most other Memory Foam over Foam mattresses. However, if you are sitting on the edge for an extended period (say, watching TV), then you might start to feel that you are not properly supported or comfortable.

Likewise, if you like to sleep right on the very edge of the bed (eg, with one arm hanging off the bed), you may notice that your body feels like it's starting to lean toward the edge -- it will be a very slow-moving lean so it would be very unlikely that you would actually roll off the bed, but the feeling of being slightly precarious would likely prevent you from wanting to sleep right there on the edge for long.

If you like the feel of memory foam, but edge support is very important to you, I would suggest you look at mattresses that use Memory Foam over Innerspring instead. Many of these models have specific features (eg, firmer foam or stiffer coils going around the perimeter of the mattress) that are designed to provide strong edge support for the use cases I mentioned above.

A good way to see and compare options like this is with our two mattress search tools, each of which provides extensive filters, so you can limit your search to only mattresses that have, for example, Comfort Material = Memory Foam and Support Material = Innerspring.